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The development of a coal-based synthetic route to produce benzene polycarboxylic acids (BPCAs) is of great importance for the highly efficient utilization of lignites. In this paper, aqueous NaCl electrolytic system was used to oxidize Zhaotong lignite to prepare BPCAs. The electrochemical oxidation of lignite in aqueous NaCl solution could produce more BPCAs than that in aqueous NaOH solution. The aqueous NaCl electrolytic system could in-suit produce a stable OCl−, which was synthesized by the combination reaction between Cl2 and OH− generated in the anode or cathode, respectively. The in-suit produced OCl− would degrade the organic structures of the lignite dispersing in the electrolyte to generate BPCAs. The formation of BPCAs could be greatly affected by current density, electrolysis time and the addition amount of NaCl in the electrolytic system, which resulted from that the factors played an important role in the generation of OCl−. The coal related model compounds including anthracene and phenanthrene were used to investigate the electrochemical oxidation mechanism of the lignite. The results indicated that the aromatic ring structures in the lignite were attacked by O2·− from the OCl− to afford BPCAs.

High performance device is the key issue for organic light‐emitting diodes (OLEDs) industrialization. In this instance, efficient hosts, emitters, as well as other functional layer materials are essential for the realization of high‐performance OLEDs. Herein, we develop a series of D−A type host materials, TPATRZ, CzTRZ, and POXTRZ with ortho‐linking strategy. The ortho‐linkage makes TPATRZ, CzTRZ, and POXTRZ highly twisted conformations, which reducing the degree of intramolecular conjugation and maintain high triplet energies of these materials. The red phosphorescence organic light emitting diodes by using Ir(piq)2(acac) as dopant, TPATRZ, CzTRZ, and POXTRZ as host materials achieved relative high device performance with over 20 % external quantum efficiency and flat efficiency roll‐off. The EQEs of the champion devices remain above 22 % at the practical luminance (500 and 1000 cd m−2). The device hosted by POXTRZ achieved the highest external quantum efficiency of 24.0 %, as well as smallest efficiency roll‐off of 6.3 % at 1000 cd m−2. These results further extend the possibilities of ortho‐linkage D−A type host materials and make them have a promising application in OLEDs. [ABSTRACT FROM AUTHOR]

The helical contour motion accuracy of feed drive axes is important for thread milling operations in computer numerical control (CNC) machine tools. However, the motion dynamics and external disturbances significantly affect the contour motion results, while the feed drive axes perform helical motions in thread milling operations. Although existing iterative learning contour control (ILCC) methods can improve contour motion accuracy, the problems of data recording and processing on memory usage and computational burden in control systems, wasted materials, and increased costs in thread manufacturing still limit the practical applications of ILCC. Therefore, considering the similar motion dynamics and external disturbances of the feed drive axes during the pitch cycle motions of a helical path, this study developed a pitch cycle-based iterative learning contour control (PCB-ILCC) method to address the control system and thread manufacturing problems caused by the use of ILCC. For PCB-ILCC, this study adopted contour error vector estimation by referring to the interpolated positions on the pitch cycle of the helical path to simplify the computational complexity and designed the ILCC using the cycle learning method to easily implement the ILCC structure. Thus, this study developed a permanent magnet synchronous motor (PMSM) driving control utilizing the robust control method to mitigate the problems of motion dynamics and external disturbances on the feed drive axes. Thread milling experiments performed on a five-axis CNC machining center demonstrated the feasibility of the PCB-ILCC and validated that it can significantly improve the helical contour motion accuracy of the feed drive axes and achieve an 80% contour error reduction rate in comparison with the proportional–proportional–integral control, which is extensively used in commercialized PMSM drivers and CNC controllers.

Abstract: Compound {(EMIM)2[Zn7(μ4-O)2(1,4-ndc)6]}n (1) (EMIM=1-ethyl-3-methylimidazolium and 1,4-ndc=1,4-naphthalenedicarboxylate) has been synthesized by using the mixed ionic liquids of 1-ethyl-3-methylimidazolium tetrafluoroborate and 1-ethyl-3-methylimidazolium l-lactate as solvent. Compound 1 has a 3D anionic framework with bcu-(424·64) topology based on a unique heptanuclear [Zn7(μ4-O)(μ2-COO)10] cluster as secondary building unit. The imidazolium cation [EMIM]+ of the ionic liquid acting as extra framework charge-balancing species occupies the channels of the 3D anionic framework. The roles of the ionic liquid in ionothermal synthesis and crystallization of compound 1 are briefly discussed. The thermal and photoluminescent properties of compound 1 have also been investigated. [Copyright &y& Elsevier]

Mobile ad hoc networks (MANETs) have become a hot issue in the area of wireless networks for their non-infrastructure and mobile features. In this paper, a MANET is modeled so that the length of each link in the network is considered as a birth-death process and the space is reused for n times in the flooding process, which is named as an n-spatial reuse birth-death model ( n-SRBDM). We analyze the performance of the network under the dynamic source routing protocol (DSR) which is a famous reactive routing protocol. Some performance parameters of the route discovery are studied such as the probability distribution and the expectation of the flooding distance, the probability that a route is discovered by a query packet with a hop limit, the probability that a request packet finds a τ-time-valid route or a symmetric-valid route, and the average time needed to discover a valid route. For the route maintenance, some parameters are introduced and studied such as the average frequency of route recovery and the average time of a route to be valid. We compare the two models with spatial reuse and without spatial reuse by evaluating these parameters. It is shown that the spatial reuse model is much more effective in routing. [ABSTRACT FROM AUTHOR]

To identify the features of Chinese genetic prion diseases.Suspected Creutzfeldt-Jakob disease (CJD) cases that were reported under CJD surveillance were diagnosed and subtyped using the diagnostic criteria issued by the WHO. The general information concerning the patient, their clinical, MRI and EEG data, and the results of CSF 14-3-3 and PRNP sequencing were carefully collected from the database of the national CJD surveillance program and analyzed using the SPSS 11.5 statistical software program.Since 2006, 69 patients were diagnosed with genetic prion diseases and as having 15 different mutations. The median age of the 69 patients at disease onset was 53.5 years, varying from 19 to 80 years. The majority of patients displaying clinical symptoms were in the 50-59 years of age. FFI, T188K gCJD and E200K were the three most common subtypes. The disease appeared in the family histories of 43.48% of the patients. The clinical manifestations varied considerably among the various diseases. Patients who carried mutations in the N-terminus displayed a younger age of onset, were CSF 14-3-3 negative, had a family history of the condition, and experienced a longer duration of the condition. The clinical courses of T188K were significantly shorter than those of FFI and E200K gCJD, while the symptoms in the FFI group appeared at a younger age and for a longer duration. Moreover, the time intervals between the initial neurologist visit to the final diagnosis were similar among patients with FFI, T188K gCJD, E200K gCJD and other diseases.The features of Chinese genetic prion diseases are different from those seen in Europe and other Asian countries.

Fluorene is a classic three-membered polycyclic aromatic hydrocarbon, and it has been widely used in optoelectronic devices. Here we explore a simple and efficient strategy for the derivatization at the 2- and 3- positions in fluorene unit. By introducing different types of substituents, we design two pairs of 2,3-disubstituted fluorene isomers and use them as host materials for phosphorescent organic light-emitting diodes (PHOLEDs). The green PHOLEDs hosted by these fluorene derivatives realize high external quantum efficiencies (EQE) over 20 % with low efficiency roll-off. Particularly, the devices hosted by 2TRz3TPA and 2TPA3TRz achieve nearly 24 % EQE and 104 lm W -1 power efficiency. These results clearly demonstrate that the 2,3-disubstituted fluorene platforms are potentially useful for constructing host materials., (© 2022 Wiley-VCH GmbH.)

Nanozymes as artificial enzymes that mimicked natural enzyme-like activities have received great attention in cancer diagnosis and therapy. Biomimetic nanozymes require more consideration regarding complicated tumor microenvironments to mimic biological enzymes, thus achieving superior nanozyme activity in vivo. Here we report a biomimetic hybrid nanozyme (named rMGB) which integrates natural enzyme glucose oxidase (GOx) with nanozyme manganese dioxide (MnO 2 ) by mutual promotion for maximizing the enzymatic activity of MnO 2 and GOx. Under hypoxia environment, we observed that MnO 2 could react with endogenous H 2 O 2 to produce O 2 for enhancing the catalytic efficiency of GOx for starvation therapy. Meanwhile, we confirmed that glucose oxidation generated gluconic acid and further improved the catalytic efficiency of MnO 2 subsequently. The biochemical reaction cycle, consisting of MnO 2 , O 2 , GOx, and H + , was triggered by the tumor microenvironment and accelerated each other so as to achieve self-supplied H + and accelerate O 2 generation, enhancing the starvation therapy, alleviating tumor hypoxia and accelerating the reactive oxygen species generation in photodynamic therapy. This biomimetic hybrid nanozyme would further facilitate the development of biological nanozymes for cancer treatment.